Effectiveness of antimalarial interventions in Nigeria: Evidence from facility‐level longitudinal data

Objective To evaluate the effectiveness of a program of antimalarial interventions implemented in 2010‐2013 in Niger State, Nigeria. Data Sources Utilization reports from 99 intervention and 51 non‐intervention health facilities from the Niger State Malaria Elimination Program, supplemented by data on facility‐level characteristics from the Niger State Primary Health Care Development Agency and Local Government Malaria Control units. Study Design Estimated with mixed‐effects negative binomial modeling, a difference‐in‐differences method was used to quantify the impact of the program on the number of febrile illness cases and confirmed malaria cases. Potential confounding factors, non‐stationarity, seasonality, and autocorrelation were explicitly accounted for. Data Extraction Methods Data were retrieved from hard copies of utilization reports and manually inputted to create a panel of 5550 facility‐month observations. Principal Findings The program was implemented in two phases. The first phase (August 2010‐June 2012) involved the provision of free artemisinin‐based combination therapies, long‐lasting insecticidal nets, and intermittent preventive treatments. In the second phase (July 2012‐March 2013), the program introduced an additional intervention: free parasite‐based rapid diagnostic tests. Compared to the pre‐intervention period, the average number of monthly febrile illness and malaria cases increased by 20.876 ( P  < 0.01) and 22.835 ( P  < 0.01) in the first phase, and by 19.007 ( P  < 0.05) and 19.681 ( P  < 0.05) in the second phase, respectively. The results are consistent across different evaluation methods. Conclusions This study suggests that user‐fee removal leads to increased utilization of antimalarial services. It motivates future studies to cautiously select their investigative methods.